CHRONIC DERMATOPHYTE INFECTIONS - PHYSIO- PATHOLOGY, TREATMENT

Purpose: Treatment of dermatophytoses, one of the most common cutaneou s superficial infections, leads to a clinical and mycological improvme nt in most of the cases, except in some patients who became chronicall y infected. Discussion: Situation in chronically infected individuals is still partly unclear: chronicity is caused rather by failure to era dicate the original infection, than by exogenous reinfestation. Patien ts with chronic Trichophyton rubrum infections are particularly likely to lack delayed-type responses in vivo. In vitro, most studies have s hown normal but variable cellular responses to dermatophyte antigen. T his T-cell suppression might be caused by several factors: an imbalanc e between T-helper lymphocyte sub-population might explain the chronic course of dermatophytoses, with preferential sensitization of Th2 cel ls, and high levels of anti-dermatophyte IgE. Presence of dermatophyte antigens in serum of chronically infected patients has been demonstra ted: purified T. rubrum mannan suppresses lymphocyte blast transformat ion. Treatment: Failure of chronic dermatophyte infections to respond to oral antifongal therapy is well known. Two fongistatic molecules ar e available: griseofulvine and ketoconazole, but they do not avoid rel apse. Terbinafine, the only drug of fongicidal effect, seems to be ver y successful in the treatment of chronic fungal diseases.